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Australopithecina or Hominina is a subtribe in the tribe
Hominini The Hominini form a taxonomic tribe of the subfamily Homininae ("hominines"). Hominini includes the extant genera ''Homo'' (humans) and '' Pan'' (chimpanzees and bonobos) and in standard usage excludes the genus ''Gorilla'' (gorillas). The ...
. The members of the subtribe are generally ''
Australopithecus ''Australopithecus'' (, ; ) is a genus of early hominins that existed in Africa during the Late Pliocene and Early Pleistocene. The genus ''Homo'' (which includes modern humans) emerged within ''Australopithecus'', as sister to e.g. ''Australo ...
'' (
cladistically Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...
including the
genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
''
Homo ''Homo'' () is the genus that emerged in the (otherwise extinct) genus '' Australopithecus'' that encompasses the extant species ''Homo sapiens'' ( modern humans), plus several extinct species classified as either ancestral to or closely rela ...
'', ''
Paranthropus ''Paranthropus'' is a genus of extinct hominin which contains two widely accepted species: '' P. robustus'' and '' P. boisei''. However, the validity of ''Paranthropus'' is contested, and it is sometimes considered to be synonymous with ''Austr ...
'', and ''
Kenyanthropus ''Kenyanthropus'' is a hominin genus identified from the Lomekwi site by Lake Turkana, Kenya, dated to 3.3 to 3.2 million years ago during the Middle Pliocene. It contains one species, ''K. platyops'', but may also include the 2 million year ...
''), and it typically includes the earlier '' Ardipithecus'', '' Orrorin'', '' Sahelanthropus'', and '' Graecopithecus''. All these closely related species are now sometimes collectively termed australopiths or homininians. They are the extinct, close relatives of humans and, with the extant genus ''
Homo ''Homo'' () is the genus that emerged in the (otherwise extinct) genus '' Australopithecus'' that encompasses the extant species ''Homo sapiens'' ( modern humans), plus several extinct species classified as either ancestral to or closely rela ...
'', comprise the human
clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...
. Members of the human clade, i.e. the Hominini after the split from the chimpanzees, are now called Hominina (''see Hominidae; terms "hominids" and hominins''). While none of the groups normally directly assigned to this group survived, the australopiths do not appear to be literally extinct (in the sense of having no living descendants) as the genera ''Kenyanthropus'', ''Paranthropus'' and ''
Homo ''Homo'' () is the genus that emerged in the (otherwise extinct) genus '' Australopithecus'' that encompasses the extant species ''Homo sapiens'' ( modern humans), plus several extinct species classified as either ancestral to or closely rela ...
'' probably emerged as sister of a late ''Australopithecus'' species such as '' A. africanus'' and/or '' A. sediba''. The term australopithecine came from a former classification as members of a distinct subfamily, the Australopithecinae. Members of ''Australopithecus'' are sometimes referred to as the "gracile australopiths", while ''Paranthropus'' are called the "robust australopiths". The australopiths occurred in the
Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million years ago) to 5.333 Ma. The ...
sub-epoch and were
bipedal Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from Latin ''bis'' 'double' ...
, and they were dentally similar to humans, but with a brain size not much larger than that of modern non-human apes, with lesser
encephalization Encephalization quotient (EQ), encephalization level (EL), or just encephalization is a relative brain size measure that is defined as the ratio between observed to predicted brain mass for an animal of a given size, based on nonlinear regress ...
than in the genus ''Homo''. Humans (genus ''Homo'') may have descended from australopith ancestors and the
genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
'' Ardipithecus'', '' Orrorin'', '' Sahelanthropus'', and '' Graecopithecus'' are the possible ancestors of the australopiths.


Classification

Classification of subtribe Australopithecina according to . *Australopithecina **''
Australopithecus ''Australopithecus'' (, ; ) is a genus of early hominins that existed in Africa during the Late Pliocene and Early Pleistocene. The genus ''Homo'' (which includes modern humans) emerged within ''Australopithecus'', as sister to e.g. ''Australo ...
'' ***''
Australopithecus africanus ''Australopithecus africanus'' is an extinct species of australopithecine which lived between about 3.3 and 2.1 million years ago in the Late Pliocene to Early Pleistocene of South Africa. The species has been recovered from Taung, Sterkfontei ...
'' ***''
Australopithecus deyiremeda ''Australopithecus deyiremeda'' is an extinct species of australopithecine from Woranso–Mille, Afar Region, Ethiopia, about 3.5 to 3.3 million years ago during the Pliocene. Because it is known only from three partial jawbones, it is unclear ...
'' ***'' Australopithecus garhi'' ***''
Australopithecus sediba ''Australopithecus sediba'' is an extinct species of australopithecine recovered from Malapa Cave, Cradle of Humankind, South Africa. It is known from a partial juvenile skeleton, the holotype MH1, and a partial adult female skeleton, the para ...
'' ***''
Australopithecus afarensis ''Australopithecus afarensis'' is an extinct species of australopithecine which lived from about 3.9–2.9 million years ago (mya) in the Pliocene of East Africa. The first fossils were discovered in the 1930s, but major fossil finds would no ...
'' (=''Praeanthropus afarensis'') ***'' Australopithecus anamensis'' (=''Praeanthropus anamensis'') ***'' Australopithecus bahrelghazali'' (=''Praeanthropus bahrelghazali'') **''
Paranthropus ''Paranthropus'' is a genus of extinct hominin which contains two widely accepted species: '' P. robustus'' and '' P. boisei''. However, the validity of ''Paranthropus'' is contested, and it is sometimes considered to be synonymous with ''Austr ...
'' ***''
Paranthropus robustus ''Paranthropus robustus'' is a species of robust australopithecine from the Early and possibly Middle Pleistocene of the Cradle of Humankind, South Africa, about 2.27 to 0.87 (or, more conservatively, 2 to 1) million years ago. It has been iden ...
'' ***''
Paranthropus boisei ''Paranthropus boisei'' is a species of australopithecine from the Early Pleistocene of East Africa about 2.5 to 1.15 million years ago. The holotype specimen, OH 5, was discovered by palaeoanthropologist Mary Leakey in 1959, and described by ...
'' ***'' Paranthropus aethiopicus'' **'' Ardipithecus'' ***'' Ardipithecus ramidus'' ***''
Ardipithecus kadabba ''Ardipithecus kadabba'' is the scientific classification given to fossil remains "known only from teeth and bits and pieces of skeletal bones", originally estimated to be 5.8 to 5.2 million years old, and later revised to 5.77 to 5.54 million ye ...
'' **'' Orrorin'' ***''
Orrorin tugenensis ''Orrorin tugenensis'' is a postulated early species of Homininae, estimated at and discovered in 2000. It is not confirmed how ''Orrorin'' is related to modern humans. Its discovery was used to argue against the hypothesis that australopitheci ...
'' **'' Sahelanthropus'' ***''
Sahelanthropus tchadensis ''Sahelanthropus tchadensis'' is an extinct species of the Homininae (African apes) dated to about , during the Miocene epoch. The species, and its genus ''Sahelanthropus'', was announced in 2002, based mainly on a partial cranium, nicknamed ''T ...
'' **'' Graecopithecus'' ***'' Graecopithecus freybergi'' ***'' Graecopithecus macedoniensis''


Phylogeny

Phylogeny of Hominina/Australopithecina according to Dembo ''et al''. (2016).


Physical characteristics

The post-cranial remains of australopiths show they were adapted to bipedal locomotion, but did not walk identically to humans. They have a high brachial index (forearm/upper arm ratio) when compared to other hominins, and they exhibit greater
sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...
than members of ''
Homo ''Homo'' () is the genus that emerged in the (otherwise extinct) genus '' Australopithecus'' that encompasses the extant species ''Homo sapiens'' ( modern humans), plus several extinct species classified as either ancestral to or closely rela ...
'' or '' Pan'' but less so than ''
Gorilla Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four ...
'' or '' Pongo''. It is thought that they averaged heights of and weighed between . The brain size may have been 350 cc to 600 cc. The postcanines (the teeth behind the canines) were relatively large, and had more enamel compared to contemporary apes and humans, whereas the incisors and canines were relatively small, and there was little difference between the males' and females' canines compared to modern apes.


Relation to ''Homo''

Most scientists maintain that the genus ''
Homo ''Homo'' () is the genus that emerged in the (otherwise extinct) genus '' Australopithecus'' that encompasses the extant species ''Homo sapiens'' ( modern humans), plus several extinct species classified as either ancestral to or closely rela ...
'' emerged in Africa within the Australopiths around two million years ago. However, there is no consensus on within which species:


Asian australopiths

A minority-held view among palaeoanthropologists is that australopiths moved outside Africa. A notable proponent of this theory is Jens Lorenz Franzen, formerly Head of Paleoanthropology at the Research Institute Senckenberg. Franzen argues that robust australopiths had reached not only Indonesia, as '' Meganthropus'', but also China: In 1957, an Early Pleistocene Chinese fossil tooth of unknown province was described as resembling '' P. robustus''. Three fossilized molars from Jianshi, China (Longgudong Cave) were later identified as belonging to an ''Australopithecus'' species. However further examination questioned this interpretation; Zhang (1984) argued the Jianshi teeth and unidentified tooth belong to ''H. erectus''. Liu ''et al''. (2010) also dispute the Jianshi-australopithecine link and argue the Jianshi molars fall within the range of ''
Homo erectus ''Homo erectus'' (; meaning "upright man") is an extinct species of archaic human from the Pleistocene, with its earliest occurrence about 2 million years ago. Several human species, such as '' H. heidelbergensis'' and '' H. antecessor ...
'': But, Wolpoff (1999) notes that in China "persistent claims of australopithecine or australopithecine-like remains continue".


See also

* ''Dawn of Humanity'' (2015 PBS film) * Human taxonomy *
Human timeline The timeline of human evolution outlines the major events in the evolutionary lineage of the modern human species, '' Homo sapiens'', throughout the history of life, beginning some 4 billion years ago down to recent evolution within ''H. sapien ...


Notes


References

* * * * * * * * * * * *


External links

*
Informative lecture on ''Australopithecines''
{{DEFAULTSORT:Australopithecine Human evolution Pliocene Hominini